Retrofit Loft Insulation

Chunks

I have a single story extension (utility and en-suite) that was built some years ago (before I purchased the house). The roof is slate tiles and the pitch finishes approx. half way up the main building.

Inside, the ceiling mirrors the angle of the roof, so sloping.

The extension (both rooms) is freezing and it appears the 30/40cm void between roof tiling and ceiling is not insulated.

Any ideas, other than taking off the slate tiles and installing insulation from above? There should be some form of moisture barrier, as far as I know, so blown insulation looks problematic.

Many thanks in advance.

JP08

Our house has a similar problem - chalet style property. I'm resigned to waiting until the roof needs to be replaced before doing anything about the insulation in the sloping areas.

The flat roofs on the dormers were Celotex insulated when I had them replaced for a similar reason.

As much of the sloping ceiling in ours is inside cupboards / wardrobes I'm considering sticking Celotex to the inside of the ceilings - at least then then at least 9/10 of the roof will be insulated (ie the flat roofs, the bits in the cupboards and the bit of the chalet style roof that is the loft - although there's only about 10cm there under a chipboard loft floor)

stator

Does the inside roof need to be sloping? Could you put in a new, flat ceiling and then insulate the roof space in the normal way?

Furts

I would not insulate from above. This would need access like scaffolding, or towers and roof ladders. You are likely to break slates, others will need ripping and re-fixing, and you, or the new insulation, may push in your plasterboard ceilings.

The plasterboard is not insulated so this suggests dubious building practice, and your plasterboard may be poorly fixed or even the wrong type.

I suggest you remove the plasterboard, then insulate, membrane and offer up moisture resistant, and/or foil backed boards correctly fixed in place.

G_M

Insulate from inside.

Either remove the plaster ceiling and start again, or add a false ceilibg with insulation between.

Cheap alternative is something like http://www.coveryourwall.co.uk/wallrock-thermal-liner.html

Chunks

Thanks for the input all. Ripping off the roof tiles isn't that compelling (although probably what needs to be done). I have to keep the internal sloping roof as is. Perhaps taking down the ceiling in part anyway is the way to go but again not making me jump for joy. Really annoying that such a simple/cheap job done at the right time of the build would have avoided the need for any remedial work but there you go.

phil24_7

Are the walls insulated as these may be leaking heat too?

Smiley_Dan

Chunks wrote: »

Really annoying that such a simple/cheap job done at the right time of the build would have avoided the need for any remedial work but there you go.

Same goes for 95% of houses being built even today.

Short term job is to do it internally as others have said.

Better job is to do it externally and have a properly warm roof structure, but that will be more involved.

Chunks

phil24_7 wrote: »

Are the walls insulated as these may be leaking heat too?

They are not, sadly. The roof, I assumed, is where most of the heat is lost so I thought damage limitation and try to improve the situation there.

lstar337

Chunks wrote: »

Really annoying that such a simple/cheap job done at the right time of the build would have avoided the need for any remedial work but there you go.

Probably done while energy was cheap, by short sighted people.

lstar337

Chunks wrote: »

They are not, sadly. The roof, I assumed, is where most of the heat is lost so I thought damage limitation and try to improve the situation there.

Shame. If you insulate the roof, the heat will hit the thermal barrier, spread sideways toward the walls, and likely escape that way.:(